Rhinosinusitis is generally described as an inflammation of the nasal cavity and/or paranasal sinuses and involves the nasal mucosa. Chronic rhinosinusitis (CRS) is diagnosed when signs or symptoms of inflammation persist for 8-12 weeks or longer. It is estimated that one out of every seven Americans suffers from chronic rhinosinusitis (CRS). Symptoms of CRS include nasal obstruction, loss of sense of smell, nasal or postnasal discharge, nasal congestion, and facial pain/pressure (typically over the affected sinus area).
CRS impairs normal physical and social functioning, and patients with CRS typically suffer from an overall poor quality of life. Moreover, CRS is often associated with other co-morbid conditions such as asthma, eczema and other media. Asthma is found in 20-35% of patients with CRS, and CRS is found in up to 75% of moderate-to severe asthmatics.
It is now known that rhinosinusitis may be caused by fungi found in mucus. It is believed that some persons have an immunologic response to certain fungi found in most, if not all, persons' mucus. This immunologic response causes activated white blood cells, eosinophils, to enter the mucus. The activated eosinophils release a major basic toxic protein into the mucus which attacks and kills the fungi, but damages the nose and sinus membranes as well. The major basic protein also injures the epithelium, which allows bacteria to infect the tissues.
One type of fungus-induced rhinosinusitis is allergic fungus rhinosinusitis (AFS). AFS is generally diagnosed by: (1) the presence of nasal polyps; (2) allergic mucin; (3) CRS evidenced by CT scan; (4) positive fungal culture or histology; and/or (5) allergy to fungi by history, skin prick test or serology. AFS often leads to or is associated with CRS.
Current treatments for fungus induced rhinosinusitis include antifungal medications to remove the antigenic burden. A topical or systemic corticosteroid may also be prescribed to control inflammation of the mucosal tissue associated with CRS. This inflammation is thought to contribute to tissue and bone destruction associated with CRS. Recently, it has been discovered that steroidal anti-inflammatories such as fluticasone propionate (FP) and beclomethasone dipropionate (BDP) having a particular particle size distribution profile provide increased bioavailability, increased efficacy and/or prolonged therapeutic effect when administered intranasally.
CRS may also be characterized by or associated with a chronic bacterial infection of the sinuses (nasal-paranasal region) which is often superimposed upon a self-perpetuating, eosinophil-rich inflammatory process in the sinuses. Currently, antibiotic therapy is indicated for up to six weeks or more for the treatment and elimination of the bacterial infection associated with CRS.